Abstract
Two types of wustite micropellets; wustite I (chemically pure) and wustite II (2.1% SiO2-containing wustite), were isothermally reduced at 900-1100°C in the flowing hydrogen, carbon monoxide and their mixtures. Surface area, optical and scanning electron microscopes and X-ray and carbon analyses were used to characterise the structural changes and to elucidate the possible mechanism of reduction. The highest rate at the initial stages was obtained in H2 and the slowest was in CO. With mixtures of gases, the rate did not vary with gas composition in a simple manner. The presence of silica enhanced the reduction in CO and retarded the reduction in H2. The addition of silica led to a significant slowing down at the latter stages of reduction in H2. The addition of small amount of CO to H2 eliminated this slowing down.
